An anal fistula generally originates from a perianal abscess, which is an infection focus formed near the anal sinuses in the local area of the anus. During its onset, there is obvious local redness, swelling, heat, and pain accompanied by the formation of a pus cavity containing pus. As the condition of the perianal abscess worsens, the local pus cavity will rupture and discharge pus, thus forming an anal fistula. After the rupture of a perianal abscess, its external opening cannot heal by itself, and there will be intermittent recurring discharge of pus. Therefore, it is necessary to carry out surgical treatment as soon as possible after the formation of an anal fistula, to prevent the enlargement of the local pus cavity or thickening of the fistula wall, which complicates later surgery and treatment and significantly impacts the patient's normal life.